This chapter describes the general concepts of PCI Express transaction routing and the mechanisms used by a device in deciding whether to accept, forward, or reject a packet arriving at an ingress port.

This chapter is from the book

This chapter is from the book

The Previous Chapter

The previous chapter introduced the PCI Express data transfer protocol. It described the layered approach to PCI Express device
design while describing the function of each device layer. Packet types employed in accomplishing data transfers were described
without getting into packet content details. Finally, this chapter outlined the process of a requester initiating a transaction
such as a memory read to read data from a completer across a Link.